A sheriff's deputy in Anne Arundel County, Md., responds to a garbled distress call from another officer at the scene of a house fire. The deputy is forced by a radio dead spot to drive several blocks away — while his colleague battles the blaze with a garden hose — before he can contact the fire department.

Across the country, in Portland, Ore., police pursue a carjacker into a wooded area and attempt to set up a security perimeter around the assailant. However, they discover their radios cannot talk to each other, even in close proximity, because their signal is overpowered by a nearby cellular transmission site.

Unfortunately, those types of hair-raising events are becoming more common among public safety workers who find themselves in crisis situations without functioning communications equipment. Public safety agencies in at least 27 states have reported multiple instances of significant radio interference involving what, in theory, are supposed to be separate, distinct public and private radio systems such as cellular phone towers and emergency medical services (EMS) walkie-talkies. Though a number of ideas on how to solve the problem have been proposed, resolving the interference issue (much less implementing its solution) is no simple matter — technically, economically or politically.

A crowded spectrum

Driven by the exponential proliferation of wireless devices, demand for prime radio spectrum “real estate” is outstripping supply, according to the Washington, D.C.-based Cellular Telecommunications and Internet Association (CTIA). Symptomatic of the overcrowded airwaves are widespread reports of cellular telephone interference with public safety communications, especially involving several thousand local police, fire and emergency agencies whose radios use frequencies within the 800 megahertz (MHz) portion of the radio spectrum. Hundreds of public safety agencies have filed formal complaints of interference with the Washington, D.C.-based Federal Communications Commission (FCC) and the Daytona Beach, Fla.-based Association of Public-Safety Communications Officials (APCO), connecting the local dots into a nationwide pattern of disrupted public safety communications.

Telecommunications technology experts are trying to understand how different types of radio systems operating in close proximity along the radio spectrum are colliding. The unanticipated interference occurs even though public safety radios are “high-site, high-power” systems while cellular systems operate using low-site, low-power transmitters. And, by most accounts, cellular phone companies are operating in full compliance with their licenses.

To date, no deaths or disasters have been linked to such interference, but a rising chorus of public safety officials and telecommunications experts say it is only a matter of time until calamity strikes. There is widespread agreement that interference is a growing crisis threatening the safety of residents and public safety officers in the field.

“Anybody who has an 800 MHz radio system is subject to interference from cell phones and other radio communications. Nobody thought it would happen, but it's a fact of life now,” says Alan Caldwell, director of government relations for the Fairfax, Va.,-based International Association of Fire Chiefs (IAFC). “Fire chiefs are saying ‘We cannot have interference. It endangers firefighters and other public safety personnel, and it endangers the public.”’

FCC tackles interference

Recently, the concerns of public safety officials have found excellent reception at the FCC. Its chairman, Michael Powell, says finding a comprehensive solution to interference is one of the agency's foremost priorities. The stakes are high — small slices of the radio spectrum could be sold to licensees for billions of dollars. So diverse competing interests are jockeying to ensure their viewpoints are considered before the FCC, which is expected to issue a definitive ruling by early 2004.

The agency has received extensive commentary and research data from local governments and public safety organizations, cellular service and radio technology providers, and others in business and industry. Though numerous approaches for mitigating interference have been proposed, opinion has coalesced around two particular positions.

The approach favored by most public safety organizations advocates wholesale rebanding of the various radio licensees within the 800 MHz spectrum. That rebanding would concentrate public safety communications and other non-cellular radio systems exclusively in one block of frequencies in the lower part of the 800 MHz spectrum. Cellular carriers then would operate a safe distance away in the higher 800 MHz frequencies or, in the case of one provider, Nextel, would entirely vacate the 800 MHz portion of the radio spectrum.

The alternative approach favored by the CTIA and most of Nextel's competitors — as well as by a few local governments, most prominently Baltimore — advocates relying on “best practices” and a so-called “toolbox” of technical fixes that can be used to solve interference when and where it occurs. Consensual swaps of radio spectrum would also be encouraged, but the approach does not include a comprehensive rebanding of the 800 MHz licenses. (However, in some variants of the approach, public safety communications would be moved to the 700 MHz spectrum, home to UHF television channels.)

Sorting through solutions

FCC decision makers apparently are still deeply divided over the best course of action. For example, John Muleta, chief of the FCC's Wireless Telecommunications Bureau, is leaning toward a rebanding solution. On the other hand, Edmund Thomas, chief of the FCC's Office of Engineering and Technology, says that the commission should opt for a technical solution.

Most players agree that rebanding represents the most comprehensive means to mitigating interference. However, notes Roger Entner, a telecom industry analyst for the Boston-based Yankee Group, “while it's probably the right solution, [rebanding is] quite a radical approach. Moving spectrum doesn't happen that often,” he says.

The high price tag of retuning public safety radio equipment to use new frequencies is a major concern — which is why Nextel has offered to chip in up to $850 million, which it estimates is the total cost to convert affected public safety licensees' radio systems.

Nextel's offer to pay for rebanding without taxpayer dollars has garnered support from an estimated 90 percent of 800 MHz licensees, including most of the officials representing cash-strapped local public safety organizations that use 800 MHz frequencies. However, Nextel's competitors and other critics assail the rebanding approach on several interrelated points.

  • The costs of rebanding could exceed $850 million. “We're concerned that Nextel's proposal doesn't contain enough money,” says Peter Roy, deputy chief technology officer for Washington, D.C. “It's very expensive to retune the equipment, and what happens if we get into the middle of rebanding and the $850 million disappears?”

    Nextel counters that “retuning has been done many times, so we have a good handle on the costs,” says Christopher Doherty, senior director for public affairs for the Reston, Va.-based company. With $8.7 billion in revenues last year, Nextel “can easily come up with the money,” according to Entner. However, “what goes into the treasury from Nextel is not necessarily what goes out of the treasury to pay for this,” he cautions.

  • Nextel is being rewarded for a problem it helped create. For Nextel's competitors, the biggest hitch with the rebanding plan is how Nextel proposes to be compensated for the radio spectrum it will give up. In return for vacating its frequency licenses in the 700 MHz, 800 MHz and 900 MHz portions of the radio spectrum — for which Doherty says the company paid $2 billion on the open market — Nextel has requested licenses to use 10 MHz of radio frequencies located in what Entner calls “really plum spectrum” in the 1.9 gigahertz (GHz) band.

    “If [Nextel] went to auction, [the 10 MHz section of the 1.9 GHz band] would be worth a lot more than the $850 million they've offered,” Entner explains. “Cingular just paid $1.4 billion for significantly less spectrum in 50 or so local markets.”

  • Less radical, less costly alternatives exist. Schaumburg, Ill.-based Motorola — whose wireless equipment is used almost exclusively by both Nextel and most public safety organizations — has not taken sides. “We're not opposing rebanding, and we filed a rebanding proposal” with the FCC, says Motorola spokesperson Steve Gorecki. “Rebanding is a policy issue that the FCC and our customers must decide for the long term.”

  • However, Motorola's input into the FCC's decision-making process has buttressed the arguments of rebanding's opponents. In response to the FCC's request for technical advice, Gorecki says that Motorola filed a letter with the commission in May in which it described the company's new receiver advances combined with best practices to form what it called a “technical toolbox” to mitigate interference.

    “It's a complex issue involving different types of interference,” Gorecki acknowledges. “But we believe a technical toolbox of solutions can be implemented depending on the type and severity of interference. Think of it as a really dense tree that blocks the sun, [and] you can use these tools to prune branches and let the sun come through while maintaining a healthy tree.”

    Some specific “best practices” recommended by Motorola include voluntary frequency swaps, additional filtering on carriers' transmitters, changes in carriers' antennas, and, if needed, adding public safety antenna sites.

    Rebanding supporters do not dismiss Motorola's recommendations. They argue instead that the technical fixes do not eliminate the need for comprehensive rebanding. Motorola's suggested improvements, “while significant and beneficial, are not a ‘technological silver bullet’ that would solve the 800 MHz interference,” argued a May 16 statement to the FCC from several organizations including APCO, IAFC and two Alexandria, Va.-based associations, the International Association of Chiefs of Police (IACP) and the National Sheriffs Association (NSA). “We work very closely with Motorola on a variety of communications issues [but] we disagree on this issue,” says IAFC's Caldwell, a former volunteer fire chief in Fairfax County, Va.

    Impact on local government

    All indications are that the FCC will issue a ruling by early next year. Though the outcome is far from certain, most observers still anticipate the agency will opt for comprehensive rebanding of the 800 MHz spectrum. However, the final decision may also include elements of the technical solutions described by Motorola.

    If the FCC decides to shuffle the 800 MHz spectrum, the complex rebanding process would take an estimated three years or more to implement nationwide. In the meantime, local public safety organizations will continue to grapple with radio interference issues. Certainly, communities purchasing new radio equipment will seek units that have the technology to cope with interference and that can be retuned easily if and when a comprehensive frequency swap is implemented.

    The experience of Washington, D.C., may be instructive for other municipalities, Roy says. The district's government recently used part of its $150 million in federal emergency funding to upgrade its radio communications systems, most of which operate within the 800 MHz spectrum. (D.C.'s police use 460 MHz radios, which are unaffected by cellular systems.)

    “We had four signal towers in the district, and we've upgraded to 10, but even though we now have very strong on-street signal here, it doesn't necessarily penetrate the old buildings,” Roy explains. “So one innovation we've made is our vehicle repeater system. [This is] a vehicle equipped with a radio signal repeater [that] pulls up outside and blasts a building with the signal, ensuring we can send and receive even very weak signals.”

    In contrast to the tens of millions of dollars spent on new towers, D.C.'s vehicle repeater system, which has been installed on 63 vehicles so far, “is very cost-effective,” Roy says. “Communities that don't have much money should look into this” as a possible technical solution to radio signal interference.

    John DeWitt is writer based in Cape Cod, Mass.

    SORTING OUT THE INTERFERENCE SOLUTIONS

    The proposed solution Rebanding Technical fixes
    Key features •High-site, high-power radio systems and low-site, low-tower cellular systems are separated and grouped into two distinct blocks within the 800 MHz portion of the radio spectrum
    •Nextel vacates all of its 700 MHz, 800 MHz and 900 MHz frequency licenses, eliminating its phone system as a cause of interference, making room for the rebanding, and freeing up additional spectrum for future public safety wireless systems
    •Nextel provides $850 million to cover the costs for retuning or converting radio equipment
    •Limited rebanding consisting of voluntary frequency swaps by licensees that cause or are impacted by interference
    •Additional filtering on carriers' transmitters and other changes in carriers' antennas to reduce interference
    •Building additional public safety antenna sites when needed to boost signal strength
    •Other new technologies under development and testing by Motorola
    •Motorola commits to offering its “technical toolbox” of fixes with “no incremental increase in the cost of radios” and “minimized cost of retrofitting existing radios”
    Major proponents •A reported 90 percent of 800 MHz spectrum licensees, including Nextel, private wireless entities and public safety communicators
    •Most organizations representing public safety communicators
    •Motorola
    •The National Association of Manufacturers and prominent users of private radio systems
    •The Cellular Telecommunications and Internet Association (CTIA)
    What proponents say •“It's the only plan that's funded, and it's the only approach that virtually eliminates the interference problem.” (Alan Caldwell, IAFC)
    •“As a result of the ‘consensus plan,’ public safety will … get more radio spectrum that they desperately need in a faster timeframe than with any other proposal in front of the FCC.” (Christopher Doherty, Nextel)
    •“We believe a ‘technical toolbox’ of solutions can be implemented depending on the type and severity of interference.” (Steve Gorecki, Motorola)
    •“As a less radical solution than rebanding, I would say whatever works and is cheaper and doesn't give special favors to one company.” (Roger Entner, Yankee Group analyst)
    What critics say •“We're concerned that Nextel's proposal doesn't contain enough money. It's very expensive to retune the equipment … and what happens if we get into the middle of rebanding and the $850 million disappears?” (Peter Roy, deputy chief technology officer, District of Columbia) •“These improvements, while significant and beneficial, are not a ‘technological silver bullet’ that would solve the 800 MHz interference.” (May 16 statement to the FCC from several organizations representing public service officials)